Chemoselectivity in the Reaction of 2‐Diazo‐3‐oxo‐3‐phenylpropanal with Aldehydes and Ketones |
| |
| Authors: | Jiantao Zhang Jiaxi Xu |
| |
| Affiliation: | State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, Faculty of Science, Beijing University of Chemical Technology, Beijing 100029, P.?R. China, (phone/fax: +86‐10‐64435565) |
| |
| Abstract: | The chemoselectivity in the reaction of 2‐diazo‐3‐oxo‐3‐phenylpropanal ( 1 ) with aldehydes and ketones in the presence of Et3N was investigated. The results indicate that 1 reacts with aromatic aldehydes with weak electron‐donating substituents and cyclic ketones under formation of 6‐phenyl‐4H‐1,3‐dioxin‐4‐one derivatives. However, it reacts with aromatic aldehydes with electron‐withdrawing substituents to yield 1,3‐diaryl‐3‐hydroxypropan‐1‐ones, accompanied by chalcone derivatives in some cases. It did not react with linear ketones, aliphatic aldehydes, and aromatic aldehydes with strong electron‐donating substituents. A mechanism for the formation of 1,3‐diaryl‐3‐hydroxypropan‐1‐ones and chalcone derivatives is proposed. We also tried to react 1 with other unsaturated compounds, including various olefins and nitriles, and cumulated unsaturated compounds, such as N,N′‐dialkylcarbodiimines, phenyl isocyanate, isothiocyanate, and CS2. Only with N,N′‐dialkylcarbodiimines, the expected cycloaddition took place. |
| |
| Keywords: | Cycloadditions Chemoselectivity Propanal, 2‐diazo‐3‐oxo‐3‐phenyl‐ Propan‐1‐ones, 3‐hydroxy‐ 4H‐1,3‐Dioxin‐4‐one |
|
|
